• Title/Summary/Keyword: Distribution of air concentration

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Distribution of Negative Air Ion Concentration in Urban Neighborhood Park by Distance to Road - A Case of Yangjae Citizen's Forest, Seoul - (도로와의 거리에 따른 도시 근린공원의 음이온 농도 분포차이 - 서울시 양재 시민의 숲을 대상으로 -)

  • Lee, Hyunjin;Lee, Dong Kun;Kim, Bomi
    • Journal of Environmental Impact Assessment
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    • v.27 no.2
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    • pp.152-169
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    • 2018
  • The purpose of this study was to analyze the effect of adjacentroads on the concentration of negative air ions in urban neighborhood park. The measured factors were negative air ion concentration, positive airion concentration, airtemperature,relative humidity, wind speed, green formation volume factor (GVZ) and distance from highway and general road. The mean negative air ion concentration was $206ea/cm^3$ and the positive air ion concentration was $416ea/cm^3$ in the influence zone of roads. On the other hand, the mean negative air ion was $339ea/cm^3$ and the positive air ion was $229ea/cm^3$ in the unaffected zone of roads, which are inner areas of the park. The difference of the negative air ion concentration according to the influence of the road was statistically significant. The negative air ion concentration model was presented by integrating the correlation analysis with the influence factors, and the explanatory power of the model was increased by adding the influence factor of the road.

Prediction of spatial distribution of air pollutants within tunnel (터널 내 대기오염물질의 공간분포 예측)

  • Park, Il-Gun;Hong, Min-Sun;Kim, Beom-Seok;Kang, Ho-Geun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.6
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    • pp.607-616
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    • 2012
  • The need for management of tunnel air quality is imminent considering the rapid increase of number and span of tunnels in Korea. To investigate spatial distribution of $CO_2$ within tunnels, $CO_2$ were measured and model simulations were performed in Namsan 1 tunnel. Results show that $CO_2$ concentrations were 250 ppm to 400 ppm higher in the exit than tunnel entrance. Also, $CO_2$ concentrations were 200 ppm to 300 ppm lower inside no ventilating vehicle than in the tunnel. Both experimental and model simulation results show that spatial distribution and concentration gradient of air pollutant inside tunnel are highly dependent on traffic density.

A Study on the Variation of Ventilation Effect for Indoor Air Pollutants by Ventilation Hole Sites (환기구 위치별 실내오염물질의 환기효과 변동에 관한 연구)

  • Lee, Jeong Joo;Lee, Ju Sang;Kim, Shin Do
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.5 no.2
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    • pp.226-240
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    • 1995
  • This research has a purpose to achieve experimental data used for design of ventilation systems necessary for indoor air quality control and their operation and management. For the study, spatial concentration distribution of indoor air quality according to pollutant site in a simplified model chamber. In low flow ventilation, flow pattern of indoor air was mainly influenced by diffusion and additionally, spatial distribution was formed by convection. Distribution of ventilation efficiency according to each pattern of model chamber was evaluated. It was confirmed that diffusion patterns of a pollutant among sites were formed, centering around main stream areas of supply and exhaust outlets.

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Determination of Size Distribution of Atmospheric Paticulates in Urban Air Using Andersen Sampler (Andersen 시료채취기를 이용한 도시대기중 부유입자상 물질의 입도분포 측정)

  • 이용근;김만구;원정호
    • Journal of Korean Society for Atmospheric Environment
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    • v.1 no.1
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    • pp.93-98
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    • 1985
  • Mass size distribution of atmospheric particulates were measured using an Andersen using an Andersen sampler in urban air. The atmospheric particulates were fractionated in eight stages of an Andersen sampler operating at 28.4$\ell/min$ and collected on polyester sheets. A quartz filter was placed behind the last stage collect permeated partculates. The size distribution of atmospheric particulates were divided around 1-2 $\mu$m into two groups, coarse and fine particulates regardless of sampling times. The variation of course particulates concentration was higher than fine particulates among sampling times. Different meterorological conditions and natural phenomena brought high variation of course particulates' concentration. The rain caused removal of coarse particulates seriously and the yellow and may take part in a increase of the course particulates in spring. The average concentration of atmospheric particulates to be collected by Andersen sampler was 170.8 $\mug/m^3$ during 3 times of sampling. Among them the average concentration of atmospheric particulates which could penetrated under a bronchi and alveoli were 70.4$\mug/m^3$ and 36.6$\mug/m^3$ respectively.

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Particle Size Distribution of Suspended Particulates in the Atmosphere of a Seoul Residential Area (한 도시 분진의 유해성 입도 분포에 대한 조사 연구)

  • Han, Eui-Jung;Chung, Yong;Kwon, Sook-Pyo
    • Journal of Preventive Medicine and Public Health
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    • v.19 no.1 s.19
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    • pp.130-136
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    • 1986
  • The particle size of suspended particulates was measured by a Anderson air sampler from Mar. 1982 to Feb. 1984 in a part of Seoul. It was concluded as follows : 1) The arithmetic concentration of suspended particulates was $147.8{\mu}g/m^3$ in Spring, 136.9 in Summer, 131.9 in Autumn and 158.1 in Winter respectively. 2) The cumulative distribution of suspended particulates size in logarithmic diagram showed similar to normal log distribution. 3) The atmospheric particulate matters showed a bimodal size distribution on the base of unit particle concentrations, which divided at approximately $2{\mu}m$ in the diameter. 4) While the fine particulates less than $2.1{\mu}m\;was\;35.4{\sim}45.0%$, the coarse particulates was $55.0{\sim}64.5%$. 5) The higher the concentration of suspended particulates, the more increased the ratio of fine particulates. The higher the concentration of suspended particulates, the lower median size of suspended particulate as well. 6) The respirable dust particulates less than $4.7{\mu}m\;was\;52.2{\sim}62.9%$ in seasonal average through the 2 year samples. With the above result, air pollution concerned with public health could be evaluated and the control measures also are suggested.

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The Influences of 5ea Breeze on Surface Ozone Concentration in Pusan Coastal Area, Korea (부산 연안역의 오존 농도에 미치는 해풍의 영향)

  • 김유근;이화운
    • Journal of Environmental Science International
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    • v.5 no.3
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    • pp.265-275
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    • 1996
  • Air pollution characteristics and the influence of sea breeze on surface ozone concentration were studied using the data measured at 7 air quality continuous monitoring stations from June to September using 3 years (1990, 1993, 1994) in Pusan coastal area. Among the 246 sea breeze days for research Period, there were approximately 89 sea breeze days (36%) from lune to September, And there were 120 the episode days (68%) of ozone greater than or equal to 60 ppb in summer season. In 89 sea breeze days, the episode day was highly marked as 56 days (63%). So, we knew that the sea breeze greatly affects the occurence of ozone episode day. the ozone concentration under the condition of the sea breeze increase about 40% in the daytime. Frequencies distribution of $O_3$ concentration for sea breeze moved toward high concentration class. The characteristics of ozone concentration in relation to meteorological conditions of sea breeze is significant because we can discover major weather factors for eastablishing an air pollution- weather forecast system. For further. study about meterological approach method for photochemical air pollution, it is necessary to explain the characteristics of atmosphere below 1, 000 m, especially concerning the formation mechanism of inversion layers. And finally, we will study the relationships to synoptic weather conditions and vertical structure and diurnal variation of local wind systems including sea breeze, and the vertical movements of atmosphere in the city.

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Effect of light intensity on the ozone formation and the aerosol number concentration of ambient air in Seoul (광도가 서울 대기의 오존 생성 및 에어로졸 수 농도에 미치는 영향)

  • Bae, Gwi-Nam;Park, Ju-Yeon;Kim, Min Cheol;Lee, Seung-Bok;Moon, Kil-Choo;Kim, Yong Pyo
    • Particle and aerosol research
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    • v.4 no.1
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    • pp.9-20
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    • 2008
  • The effect of light intensity on the ozone formation and the aerosol number concentration during the photochemical reactions of ambient air was investigated in an indoor smog chamber. The smog chamber consists of a housing, 64 blacklights, and a $2.5-m^3$ reaction bag made of Teflon film. The bag was filled with the unfiltered ambient air in Seoul from January 10 to March 18, 2002. In this work, the photolysis rate of $NO_2$, $k_1$ was used as an index of light intensity. Three levels of light intensity were controlled by changing the number of blacklights turned on among 64 blacklights: $0.29min^{-1}$ (50%), $0.44min^{-1}$ (75%), $0.57min^{-1}$ (100%). The ozone concentration increased rapidly within 10 minutes after irradiation irrespective of light intensity, thereafter it increased linearly during the irradiation. The ozone production rate seems to be dependent on both the light intensity and the quality of ambient air introduced into the reaction bag. The change in aerosol number concentration also depended on both the light intensity and the ambient air quality, especially aerosol size distribution. Based on the initial ambient aerosol size distributions, the photochemical potential for aerosol formation and growth is classified into two cases. One is the case showing aerosol formation and growth processes, and the other is the case showing no apparent change in particle size distribution.

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A Study on the Distribution of Air Pollutant Concentration According to Micrometeorological Characteristics (미기상 특성에 따른 대기오염 농도분포에 관한 연구)

  • Kim, Yoo-Keun;Hong, Jung-Hae;Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.3 no.1
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    • pp.31-38
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    • 1994
  • The diffusion of the pollutants released into atmosphere is dependent on its chemical reaction, topography and micrometeorological characteristics. The purpose of the study is to investigate how much micrometeorological characteristics such as stability, wind speed and mixing height affect the diffusion of the air pollutants. For this purpose, this paper let 1) the basic theory be K-theory, 2) eddy diffusivity and wind speed be dependent on mixing height and stability, and 3) Grout method be used for numeric calculation. The result was 1) the more unstable condition, the higher mixing height and the higher wind speed we, the lower pollutants concentration appears, 2) the most intensive effect on the distribution of the pollutant concentration is the atmospheric stability.

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